Virtual private networks (“VPNs”) provide users with a secure and restrictive private network within a public telecommunication infrastructure, such as the Internet. A VPN may allow for a host computer to send and receive data across shared and/or public networks, as if the host computer is an integral part of the private network with all the functionality, security and management policies of the private network.
The VPN connection across the Internet is technically a wide area network (“WAN”) link between the sites. More specifically, a VPN may be established using virtual point-to-point connections via dedicated connections, encryption, or any combination thereof. From a user perspective, the extended network resources are accessed in the same way as resources available from the private network. To prevent disclosure of private information, VPNs typically allow only authenticated remote access and make use of encryption techniques. For instance, VPNs operate by using the shared public infrastructure while maintaining privacy through security procedures and tunneling protocols. Accordingly, by encrypting data at the sending end and decrypting it at the receiving end, these tunneling protocols send the data through a “tunnel” that cannot be “entered” by data that is not properly encrypted. An additional level of security may encrypt not only the data, but the originating and receiving network addresses, as well.